Professor Barry Furrow discussed a Pennsylvania law that bars doctors from disclosing information about chemicals used in natural gas drilling that may have sickened their patients on NPR’s All Things Considered on May 17.

The law enables doctors to find out what chemicals natural-gas drillers have used in order to determine if exposure to certain substances may account for a patient’s illness. But in order to obtain the names of chemicals that drillers consider to be trade secrets, doctors must sign an agreement not to disclose the information.

“The law is vague,” Furrow said. “They haven’t defined the boundaries of disclosure, so doctors are properly nervous.”